1. Field of the Invention
The present invention relates to a toughened glass fabrication method and a toughened glass fabricated thereby, and more particularly, to a toughened glass fabrication method in which the productivity of a large toughened glass and the strength variation of the toughened glass can be improved and a toughened glass fabricated thereby.
2. Description of Related Art
Recently, the size of glass panels is rapidly increasing as their application is expanding from small mobile articles to large flat display devices, such as a monitor and a TV.
In addition to the increased size, the trend of glass panels is toward a light and thin profile in order to decrease the weight and thickness of glass panels, and studies on a glass toughening method capable of compensating for structural vulnerability resulting from the light and thin profile are also being performed.
The glass toughening method can be generally divided into a physical toughening method and a chemical toughening method. In these methods, the chemical toughening method uses the principle of inducing a compressive stress layer in the surface of a glass panel by ion exchange treatment.
In the chemical toughening method of the related art, the ion exchange treatment supplies ions to glass by dipping the glass into a salt bath which contains a molten salt. Here, the process of exchanging ions between the glass surface and the molten salt is enabled as ions penetrate into the glass dipped in the salt bath by diffusion due to the difference in concentration in the atmosphere having an increased temperature.
However, this toughening method of the related art requires the glass panel to be dipped in the state in which it is erected and fitted into a cassette. This consequently requires the volume of a heat treatment furnace to be increased. When large glass panels are strengthened, the amount becomes restricted as a result of the limited capacity.
In addition, when the toughening method of the related art is performed on a large area, variations may easily occur due to changes in heat, ion concentration or the like that are caused by a minute flow of the solution inside the bath, and non-uniformity in stress or the like may occur due to a stress change in the glass surface, so that the glass is fractured during the chemical toughening process.
The information disclosed in the Background of the Invention section is provided only for better understanding of the background of the invention, and should not be taken as an acknowledgment or any form of suggestion that this information forms a prior art that would already be known to a person skilled in the art.